On my laptops device (QWERTY) there are some ridges on the F and J buttons, what are they for?

Wow I didn't read all the comments but was surprised by how many people didn't know what the ridges were for. Like the favored answer I was taught that the ridges on F and J were to signal a touch typist were each key is. They are called Home Keys. They are not for the blind. Story Abuse